SC79

yes it does! My ecu was rebuilt right before I bought the car by tannin so I didn’t think that was the issue. I originally thought 1-3 worked and od didn’t because of the rev I was at highway speeds and maybe my converter was stalling 2nd but I just found a service manual showing what the rpm’s should be and it got me thinking, then I tested and verified I don’t have second at all. So either the harness somewhere is shorted out the ecu was fixed poorly

tonythe93sc400

Yep. That's now I did it. I have another SC and I noticed that if my OD wasn't working and it was just "bogging" in 2nd, then my rpms should be higher.
So I figured my 2nd must be missing.
If I were you, I'd try to find another ECU to test with.

SC79

mine is a 92 sc400 with the 3.92 rear gears, what rpm are you at around 70mph? I’m at like 26-2700 which is why i thought od wasn’t working because I thought it should be lower, but now I’m figuring out that that’s normal and the gear I didn’t have is 2nd and it makes the car lame to drive because of the such long gears it has lmao

tonythe93sc400

Yeah that sounds about right on the rpm. But now I have a Supra LSD so it's a bit lower for me.

SC79

I got my ecu rebuilt with a guy that everyone recommended he even sent me a video of it running another 400. I have the same issues still so it’s gotta be some wiring somewhere

tonythe93sc400

Mine turned out to be the ECU. I bought a rebuilt ECU and the issue is now gone.

SC79

yea the next day I pulled the abs fuse and then it works perfect now. Ecu was definitely the issue

SC400slide

iTrader: (11)

I had transmission issues on my 400 and went down the wrong rabbit hole replacing trans sensors and extensive diagnostics. Turned out it was just an ECU that needed some love. Not the first time for me but hopefully be the last. These cars have been around long enough that we know what commonly fails. Any new uncommon issues and blame the ECU. 8/10 times you'd be right. Glad to hear you got it fixed!

tonythe93sc400

The previous owner of mine replaced everything in the trans. Valve body, solenoids, sensors. Couldn't figure it out but paid 1000s. I bought the ECU for $300 and it was fixed immediately and the car felt totally reenergized.